Leaf-type expansible shaft with trapper bar

ABSTRACT

An improved leaf-type air shaft wherein one leaf member, of a plurality of expansible leaf members, is fixed on the exterior of the shaft, with a lateral edge portion forming a fixed jaw to cooperate with a trapper bar movable on a row of buttons arranged along the length of an air bladder within the shaft, the trapper bar forming a clamping means suitable for holding the leading edge of paper to be rolled up upon the shaft. The row of buttons itself may form the movable clamping means. The fixed leaf makes the shaft asymmetrical when the other leaves are retracted.

llnitew States Patent Smith Feb. 4, 1975 1,051,352 12/1966 Great Britain.1242/72 [75] Inventor: Geoffrey Smith, Nashua, NH. Primary Examinerjohn Huckert Assignee; Nim-cor Inc. Nashua Assistant Examiner-JohnJillions [22] ed Apr 2 3 Attorney, Agent, or Firm-Pearson & Pearson [21]Appl. No.: 346,769

[57] ABSTRACT [52] US. Cl. 242/72 B, 242/74.l [51] Int. Cl B65h 75/24,B65h 75/28 An improved leaf type air Shaft wherein one leaf [58] FieldOf Search 242/74.1, 74.2, 74, 78.3, member of a plurality f expansible fmembers, i 242/72 72 fixed on the exterior of the shaft, with a lateraledge portion forming a fixed jaw to cooperate with a trap- [56]References C'ted .per bar movable on a row of buttons arranged alongUNITED STATES PATENTS the length of an air bladder within the shaft, thetrap- 1,845,526 2/1932 Spence 242/74.2 X Pe bar forming a clamping meanssuitable for holding 2,351,894 6/1944 Allardt 242/74.l X the leadingedge of paper to be rolled up upon the 2,352,042 6/1944 Linde....242/74.1 X shaft. The row of buttons itself may form the movable2,723,805 11/1955 Herr 242/72 clamping means The fixed leaf makes theshaft asym- 2,950,071 8/1960 Tidland 242/72 B metrical when the otherleaves are retracted.

FOREIGN PATENTS OR APPLICATIONS 8,537 l0/l955 Germany 242/72 9 Claims, 4Drawing Figures PATENTED FEB 4 75 9 i W on on o I O LEAF-TYPE EXPANSIBLESHAFT WITH TRAPPER BAR BACKGROUND OF THE INVENTION Expansible leafrolls, sometimes called leaf-type air shafts, are known in theweb-processing art. Usually, they comprise three elongate leaf memberseach of which has something less than a 120 arc and, when arrangedtogether, form what may generally be considered as the outer cylinder ofan elongate roll. These leaf members are spaced from one another andattached to buttons, in turn radially movable by an air bladder withinthe shaft. Inflating and deflating the air bladder within the cylinderincreases and decreases the effective diameter of the shaft, therebyeither tightening or loosening a web of paper wrapped about the shaft,or the grip on a core of a roll of paper on the shaft. Such a leaf shaftis disclosed in US. Pat. No. 3,053,467.

It has been a problem to achieve a quick and convenient attachment ofpaper to these rolls, especially in situations where the paper has a lowfriction coefficient. Assuring a sufficient wrapping of paper to startwinding properly takes time and requires judgement by the operator. Thusit has been desirable to provide an improved means for obtaining theinitial attachment of paper to the leaf shaft, one which will notinterfere with a prime advantage of the leaf shaft, i.e., assuring easyrelease of the roll from the shaft after the completion of the windingaction.

SUMMARY OF THE INVENTION Therefore, a principal object of the inventionis to provide a leaf-type shaft which comprises means to hold the leadend of a sheet to be wound about the shaft, but does so withoutinterfering with the easy release of a roll once the winding has beencompleted.

Another object of the invention is to provide a leaf type air shaft ofthe type described which is economical to manufacture and easilyoperated by semi-skilled workmen.

Other objects of the invention will be obvious to those skilled in theart on reading the instant application.

The, above objects have been substantially achieved by the constructionof a leaf-type cylindrical air shaft wherein one of the leaves ispositioned permanently in asymmetrical position, i.e., positioned sothat it is not subjected to substantial radial movement by the inflationor deflation of an air bladder axially arranged within the shaft, butinstead constitutes a jaw fixed in expanded location. Below this leaf,or fixed jaw, is positioned a bar member, or movable jaw member, whichis radially moved by increasing or decreasing the pressure in the airbladder. The movable jaw member can thus be moved to grip the lead endofa web against the stationary leaf or fixed jaw.

ILLUSTRATIVE EMBODIMENT OF THE INVENTION In this application andaccompanying drawings, there is shown and described a preferredembodiment of the invention and suggested various alternatives andmodifications thereof, but it is to be understood that these are notintended to be exhaustive and that other changes and modifications canbe made within the scope of the invention. These suggestions areselected and included for purposes of illustration in order that othersskilled in the art will more fully understand the invention and theprinciples thereof and will be able to modify it in a variety of forms,each as may be best suited in the condition of a particular case.

IN THE DRAWINGS FIG. 1 is a view, partially in section, of a leaf-typeair shaft constructed according to the invention;

FIG. 2 is an end view in section, on line 2-2 of FIG. 1, showing theshaft unexpanded;

FIG. 3 is a view similar to FIG. 2, showing the shaft expanded andgripping a tail-end of a roll; and

FIG. 4 is a view similar to FIG. 2, showing the row of buttons servingas the clamping, or trapper, means.

Referring to FIG. 1, it is seen that a shaft 10 comprises an internalexpansion chamber 12 formed of an expansible cylinder wall 13 into whichfluid, usually air, is passed through an air valve 14 to alternatelyexpand and contract expansion chamber 12, as is desirable.

Mounted along and attached to outer surface 16 of wall 13 are plates 18,which plates serve to support leaf-securing buttons 20. Theleaf-securing buttons 20 protrude through holes 21 in intermediatecylinder 22 and are fastened to each of two external elongate leafmembers 24 by screws 23. A third elongate leaf member 24fis not attachedto any buttons 20, but, as is best seen in FIG. 2, is directly attachedto intermediate support cylinder 22 by elongate spacer bars 26. Spacerbars 26 hold leaf member 24fin a fixed radial position, independent ofthe state of inflation of chamber 12 of inflatable tube 13.

Below and proximate one lateral edge 28 of fixed leaf 24f is an elongatecompression bar member 30, which is attached to plates 32 by a row ofconnecting buttons 34. Bar 30 has a rounded outer head 33 whichapproximately conforms to a segment of the rounded inner surface 36 ofleaf 24]. The edge 28 of leaf 24f, which is proximate bar 30, is curvedoutwardly and away from bar 30. The adjacent edge 40 of the adjacentleaf 24 is curved downwardly and inwardly toward the compression barmember.

These curved edges form a tapered slit, or mouth, through which sheets42 of paper, cloth, plastic or other such web materials may be safelypositioned into a nip 44 formed by bar 30 and leaf 24f.

In operation, shaft 10 is initially in a deflated condition, that ischamber 12 is sufficiently deflated that leaves 24 outline an innercylindrical shaft configuration of reduced diameter, while leaf 24foutlines a portion of an outer cylinder. Thus leaf 24f makes shaft 10asymmetrical when deflated, but symmetrical when inflated. This, ofcourse, is because of the rigid connection of leaf 24f to supportcylinder 22 by spacer bars 26. However, deflation of chamber 12 doesallow the retraction of trapper bar 30 and causes a nip 44 to be formedbetween bar 30 and leaf 24f. The paper web is inserted into this nip 44.Thereupon chamber 12 is inflated and the paper web is compressed betweentrapper bar 30 and leaf 24f. After the web is wound upon shaft 10, it iseasily removed therefrom by deflating chamber 12, causing the roll ofpaper to loosen on the shaft.

It should be noted that a series of apertures 46 in leaf 24f may beprovided to form means to visually inspect the position of the paperwithin the nip. Slightly elongated apertures with index marks 48 are amaterial aid in assuring the desirable alignment of the paper in nip 44.

it is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed and all statements of the scope of the invention which mightbe said to fall therebetween.

As shown in FIG. 1 the elongate compression bar 30 need not becontinuous but may be discontinuous and formed of segments 52 asindicated at 50.

As shown in FIG. 4 the compression means, or elongated clamping means 54need not be a continuous trapper bar 30, or a discontinuous bar 50, butmay consist only of the spaced connector members, or buttons 56 operableas a moving jaw against the fixed jaw formed by the leaf 24]".

I claim:

1.ln a leaf type air shaft of the type comprising a generallycylindrical outer surface formed of several elongate, radially movableleaf members, an intermediate cylinder having apertures for radiallymovable buttons and a fluidic expansion chamber arranged axially withinsaid cylinder, said chamber radially moving said buttons to change theeffective diameter of said surface formed by said leaves, theimprovement wherein:

one said leaf member is immovably supported in fixed radial position onsaid intermediate cylinder, said member having one axially-extendinglateral edge portion spaced from said cylinder and having an innersurface forming a stationary clamping jaw; and

a movable compression means on said shaft, oppositely disposed to saidinner surface in said space, and under said lateral edge portion of saidone leaf member, said compression means being operably connected throughsaid apertures to said chamber for radial movement by expansion andcontraction thereof and said compression means having an outer surfaceforming a movable clamping jaw serving to hold a sheet against the innersurface of said fixed leaf member when said chamber is expanded.

2. Apparatus as defined in claim 1 wherein:

said compression means is an elongated continuous bar mounted adjacentsaid one lateral edge of said fixed leaf and said outer surface isgenerally shaped to conform to the shape of said inner surface of saidleaf, both said surfaces being arcuately curved.

3. Apparatus as defined in claim 2, wherein:

said lateral edge of said fixed leaf is curved outwardly and away fromsaid compression bar; and

the next adjacent edge of a movable leaf is curved inwardly and towardsaid compression bar.

4. Apparatus as defined in claim 1, wherein:

said compression means is one axially extending row of said buttons eachradially movable in said apertures in said shaft and collectivelyforming the said outer surface to form a radially movable clamp.

5. Apparatus as defined in claim 2, wherein:

said compression bar is fixed to the tips of a row of said radiallymovable buttons.

6. Apparatus as defined in claim 2, wherein:

said compression bar is mounted adjacent one lateral edge of said fixedleaf member; and includes a curved outer face;

said lateral edge of said fixed leafis curved outwardly and away fromsaid compression bar; and

the next adjacent edge of a movable leaf is curved inwardly and towardsaid compression bar.

7. Apparatus as defined in claim 2, wherein:

said intermediate cylinder includes a recess;

said compression bar, when in retracted position, is

adapted to be partially received in said recess.

8. Apparatus as defined in claim 2, wherein:

said compression bar is elongated but discontinuous and each segmentthereof is radially movable and affixed to at least one button, radiallymovableby said expansion chamber.

9. In an expansible shaft of the type having outwardly movable leavesextending along, and around, an intermediate cylinder, the combinationof:

a plurality of said elongated leaves spaced around said cylinder, onesaid leaf being fixed to said cylinder in asymmetrical position todefine a portion of a cylinder outlined when all of said leaves areexpanded and having one axially extending lateral edge portion spacedfrom said cylinder to form a space therewith for receiving an end of aweb;

the other said leaves being normally retracted but radially movableoutwardly to define said cylindrical outline with said fixed leaf;

elongated clamping means on said intermediate cylinder, oppositelydisposed to, and under, the lateral edge portion of said fixed leaf, insaid space, for gripping said end of said web against said lateral edgeportion of said fixed leaf, said means being radially movable in saidspace;

and means for moving said outwardly movable leaves and said clampingmeans radially inwardly and outwardly.

1. In a leaf type air shaft of the type comprising a generallycylindrical outer surface formed of several elongate, radially movableleaf members, an intermediate cylinder having apertures for radiallymovable buttons and a fluidic expansion chamber arranged axially withinsaid cylinder, said chamber radially moving said buttons to change theeffective diameter of said surface formed by said leaves, theimprovement wherein: one said leaf member is immovably supported infixed radial position on said intermediate cylinder, said member havingone axially-extending lateral edge portion spaced from said cylinder andhaving an inner surface forming a stationary clamping jaw; and a movablecompression means on said shaft, oppositely disposed to said innersurface in said space, and under said lateral edge portion of said oneleaf member, said compression means being operably connected throughsaid apertures to said chamber for radial movement by expansion andcontraction thereof and said compression means having an outer surfaceforming a movable clamping jaw serving to hold a sheet against the innersurface of said fixed leaf member when said chamber is expanded. 2.Apparatus as defined in claim 1 wherein: said compression means is anelongated continuous bar mounted adjacent said one lateral edge of saidfixed leaf and said outer surface is generally shaped to conform to theshape of said inner surface of said leaf, both said surfaces beingarcuately curved.
 3. Apparatus as defined in claim 2, wherein: saidlateral edge of said fixed leaf is curved outwardly and away from saidcompression bar; and the next adjacent edge of a movable leaf is curvedinwardly and toward said compression bar.
 4. Apparatus as defined inclaim 1, wherein: said compression means is one axially extending row ofsaid buttons each radially movable in said apertures in said shaft andcollectively forming the said outer surface to form a radially movableclamp.
 5. Apparatus as defined in claim 2, wherein: said compression baris fixed to the tips of a row of said radially movable buttons. 6.Apparatus as defined in claim 2, wherein: said compression bar ismounted adjacent one lateral edge of said fixed leaf member; andincludes a curved outer face; said lateral edge of said fixed leaf iscurved outwardly and away from said compression bar; and the nextadjacent edge of a movable leaf is curved inwardly and toward saidcompression bar.
 7. Apparatus as defined in claim 2, wherein: saidintermediate cylinder includes a recess; said compression bar, when inretracted position, is adapted to be partially received in said recess.8. Apparatus as defined in claim 2, wherein: said compression bar iselongated but discontinuous and each segment thereof is radially movableand affixed to at least one button, radially movable by said expansionchamber.
 9. In an expansible shaft of the type having outwardly movableleaves extending along, and around, an intermediate cylinder, thecombination of: a plurality of said elongated leaves spaced around saidcylinder, one said leaf being fixed to said cylinder in asymmetricalposition to define a portion of a cylinder outlined when all of saidleaves are expanded and having one axially extending lateral edgeportion spaced from said cylinder to form a space therewith forreceiving an end of a web; the other said leaves being normallyretracted but radiallY movable outwardly to define said cylindricaloutline with said fixed leaf; elongated clamping means on saidintermediate cylinder, oppositely disposed to, and under, the lateraledge portion of said fixed leaf, in said space, for gripping said end ofsaid web against said lateral edge portion of said fixed leaf, saidmeans being radially movable in said space; and means for moving saidoutwardly movable leaves and said clamping means radially inwardly andoutwardly.